A circular stapler is a kind of medical appliance often used in surgical operation of physiological tissues such as digestive tracts. These kinds of staplers often use a type of axial inner stapling. In anastomosis, two tissues move towards each other and form a circular anastomotic ring inside the tissues. The appliance is capable of discharging the tissue blood generated in the operation together with the contents, which facilitates healing of the tissues after surgery.
Currently, the circular stapler includes a staple body and an anvil assembly for mating with the staple body. The staple body includes an annular staple cartridge and a cutter both located at a far end thereof. The anvil assembly includes a cone-shaped anvil, an anvil cap fixed on top of the anvil assembly, an annular cutting pad set inside the anvil and an anvil shaft for connecting the staple body. The anvil assembly is connected to the staple body through the anvil shaft, and is capable of conducting reciprocating movement. In anastomosis, firstly, the anvil of the anvil assembly and the staple cartridge of the staple body can tightly clamp two tissues, and then the two tissues can be anastomosed by the staples sent from the staple cartridge and associated with the anvil. At the same time, the cutter is pushed out to cut off the excessive tissues.
Generally, the physiological tissues such as digestive tracts anastomosed by the circular stapler, the tissues are firstly cut by the surgical cutter. The surgical cutter will leave staples on the severed tissues. When using the circular stapler to anastomose the tissues, such staples would likely cause that the anastomotic cross does not be successfully cut off, but also it will drag the tissues. As a result, at the new anastomotic position, the tissues are torn off or the new staples can not be normally formed.